Israeli government spokesman Mark Regev said it still has hundreds of targets in its sights.

"We will hit the Hamas military machine, we'll hit their command and control, we'll hit their arsenals, we'll hit their rocket-launching sites, we will strike at those who've been firing rockets at our civilians," he said.

"When this is over, one way or another, they'll have a situation where there is quiet in the south and rockets will no longer be fired at Israeli civilians, that's our bottom line."

International reaction

US president Barack Obama has turned to Turkey for help in a bid to stop the conflict between Israel and Hamas.

The White House says Mr Obama called Turkey's prime minister, Tayyip Erdogan, before the Turkish leader flew to Cairo, where the Arab League is holding emergency talks on Gaza.

Mr Obama is believed to be pressing both Turkey and Egypt to broker a truce between Hamas and Israel.

Egyptian president Mohamed Mursi has said there were "some indications" a ceasefire could be reached soon, but he had no firm guarantees.

Egypt brokered an informal truce in October, which has since collapsed.

The Arab League has given its backing to Egyptian efforts to secure a deal that would end Israel's offensive on Gaza.

A statement from the group said Arab foreign ministers would form a delegation to travel to the Palestinian territory in a show of support.

Arab League chief Nabil Elaraby told reporters he would lead the delegation, and the trip was expected to take place in the next "one or two days".

The statement also condemned what it called Israeli "aggression" and expressed "complete discontent" at the United Nations Security Council's failure to bring about a ceasefire.

The Arab League has also decided to review its diplomacy towards Israel and the overall Middle East peace process.

Australia's foreign minister Bob Carr said the Government supports efforts to prevent further fighting.

"I underline again that we want both sides to move towards a truce and we see value in the role of Egypt in facilitating such an understanding," he said.

"We say that account must be taken of civilian casualties, that Israel should be aware of the risk its own troops will be in - the risk of injury, death or kidnapping - and Israel should be aware of the danger of feeding extremism by what might be seen as a disproportionate reaction."